Persistence of pyrimidine dimers during post-replication repair in ultraviolet light-irradiated Escherichia coli K12

We have used a new assay for pyrimidine dimers to obtain evidence regarding the mechanism of post-replication repair of ultraviolet light-induced damage in excision-deficient (uvr) mutants of Escherichia coli. Our data indicate that dimers are gradually removed from the irradiated DNA under conditions permitting post-replication repair. Concomitantly, dimers appear in daughter strands synthesized after irradiation. The daughter strands initially contain gaps. During post-replication repair the gaps are filled and the originally discontinuous DNA is joined into long molecules resembling those observed in unirradiated control cells. Density transfer experiments reported by other investigators have provided evidence that the gap-filling involves exchanges between irradiated parental DNA and unirradiated daughter strands. The results of our experiments are in accord with this possibility and suggest that some dimers are included in the exchanged regions. Our data imply that intact, dimer-free DNA molecules are not necessarily generated by gap-filling and may not appear in uvr cells until several hours after u.v. irradiation. Instead, dimers may be gradually diluted among successive generations of DNA molecules synthesized after irradiation.     

Graphitic Carbon Nanocage as a Stable and High Power Anode for Potassium‐Ion Batteries

As an emerging electrochemical energy storage device, potassium‐ion batteries (PIBs) have drawn growing interest due to the resource‐abundance and low cost of potassium. Graphite‐based materials, as the most common anodes for commercial Li‐ion batteries, have a very low capacity when used an anode for Na‐ion batteries, but they show reasonable capacities as anodes for PIBs. The practical application of graphitic materials in PIBs suffers from poor cyclability, however, due to the large interlayer expansion/shrinkage caused by the intercalation/deintercalation of potassium ions. Here, a highly graphitic carbon nanocage (CNC) is reported as a PIBs anode, which exhibits excellent cyclability and superior depotassiation capacity of 175 mAh g^?1 at 35 C. The potassium storage mechanism in CNC is revealed by cyclic voltammetry as due to redox reactions (intercalation/deintercalation) and double‐layer capacitance (surface adsorption/desorption). The present results give new insights into structural design for graphitic anode materials in PIBs and understanding the double‐layer capacitance effect in alkali metal ion batteries.     

Elimination of I131-labelled heterologous antigen from the blood of chickens after total body X-irradiation

A study was made on the effect of ionizing radiation upon the rate of elimination of I¹³¹. labelled human serum albumin (HSA I¹³¹) from the blood and upon antibody formation in chickens irradited with 1,2 00R(i.e.with LD₅₀) and injected with antigen 30 min, 6 days or 14 days after irradiation. The elimination curve from unirradiated control birds followed the typical three-phase pattern. The effect of irradiation was most marked with chickens injected with antigen 6 days after irradiation, resulting in an extension of the second phase with practically no third phase at all. Exposure to irradiation 30 min prior to antigen administration resulted in an extension of the second phase by 2 days as compared to the controls, with the onset of the third phase occurring on day 7. Irradiation 14 days prior to antigen administration resulted in an extension of the second phase by 1 day as compared to the controls, with the onset of the third phase occurring on day 6. Elimination of HSA I¹³¹ in the second phase was more rapid than that of I¹³¹-labelled chicken serum albumin (CSA I¹³¹) no matter whether the chickens were irradiated or not. This suggests that the capacity of specific antigen uptake is not affected by irradiation. Antigen elimination curves from control irradiated groups given CSA I¹³¹ followed the same pattern as that found in control unirradiated birds injected with homologous antigen.     

Formation of Uniform N‐doped Carbon‐Coated SnO2 Submicroboxes with Enhanced Lithium Storage Properties

Rational design and preparation of SnO₂‐based materials with superior electrochemical performance for lithium‐ion batteries are highly desirable. In this work, the synthesis of SnO₂/nitrogen‐doped carbon (SnO₂/NC) submicroboxes with excellent lithium storage properties is reported. The as‐synthesized SnO₂/NC submicroboxes are highly porous with a high specific surface area of 125 m² g^?1, well‐defined hollow structure (around 400 nm in size) with a shell thickness of 40 nm, and ultrasmall SnO₂ nanoparticles uniformly coated with nitrogen‐doped carbon layer. As a result, the SnO₂/NC submicroboxes show outstanding electrochemical performance as an anode material for lithium‐ion batteries. A high reversible capacity of 491 mAh g^?1 can be retained after 100 cycles at a current density of 0.5 A g^?1.     

Boosting Sodium Storage in TiF3/Carbon Core/Sheath Nanofibers through an Efficient Mixed‐Conducting Network

Sodium‐ion batteries (SIBs) are considered to be promising energy storage devices for large‐scale grid storage application due to the vast earth‐abundance and low cost of sodium‐containing precursors. Designing and fabricating a highly efficient anode is one of the keys to improve the electrochemical performance of SIBs. Recently, fluoride‐based materials are found to show an exceptional anode function with high theoretical specific capacity, based on open‐framework structure enabling Na insertion and also exhibiting improved safety. However, fluoride‐based materials suffer from sluggish kinetics and poor capacity retention essentially due to low electric conductivity. Here, an efficient mixed‐conducting network offering fast pathways is proposed to address these issues. This network relies on titanium fluoride?carbon (TiF₃?C) core/sheath nanofibers that are prepared via electrospinning. Such highly interconnected electrodes exhibit an enhanced and faster sodium storage performance. Carbon sheath nanofibers are key to an efficient ion‐ and electron‐conducting network that enable Na⁺/e^? transfer to reach the nanosized TiF₃. In addition, in‐situ‐converted Ti and NaF particles embedded in the carbon matrix allow high reversible interfacial storage. As a result, the TiF₃?C core/sheath electrode exhibits a high capacity of 161 mAh g^?1 at a high current density of 1000 mA g^?1 over 2000 cycles.     

Glass‐Ceramic‐Like Vanadate Cathodes for High‐Rate Lithium‐Ion Batteries

Nanostructured electrode materials are good candidates in batteries especially for high‐rate applications, yet they often suffer from extensive side reactions due to anomalously large surface areas. While micrometer‐size materials provide better stability, the lattice diffusivity is often too slow for lithium ion intercalation over the same length scale in a short time. Herein, a simple method to synthesize glass‐ceramic‐like vanadate cathodes for lithium‐ion batteries with abundant internal boundaries that allow fast lithium ion diffusion while maintaining a small surface area that thus minimize the contact and side reactions with organic electrolyte, is reported. Such samples heat‐treated under optimized conditions can deliver an impressive high‐rate capacity of 103 mAh g^?1 at 4000 mA g^?1 over 500 cycles, which has better kinetics and cycling stability than similar vanadate‐based materials. A striking grain‐size refinement effect accompanied by a low‐temperature growth‐controlled phase transition, can be achieved by fine tuning the heat‐treatment process. It is believed that the findings are general for other transition metal oxides for energy applications.     

A Novel Dendrite‐Free Mn2+/Zn2+ Hybrid Battery with 2.3 V Voltage Window and 11000‐Cycle Lifespan

With the increasing energy crisis and environmental pollution, rechargeable aqueous Zn‐based batteries (AZBs) are receiving unprecedented attention due to their list of merits, such as low cost, high safety, and nontoxicity. However, the limited voltage window, Zn dendrites, and relatively low specific capacity are still great challenges. In this work, a new reaction mechanism of reversible Mn²⁺ ion oxidation deposition is introduced to AZBs. The assembled Mn²⁺/Zn²⁺ hybrid battery (Mn²⁺/Zn²⁺ HB) based on a hybrid storage mechanism including Mn²⁺ ion deposition, Zn²⁺ ion insertion, and conversion reaction of MnO₂ can achieve an ultrawide voltage window (0–2.3 V) and high capacity (0.96 mAh cm^?2). Furthermore, the carbon nanotubes coated Zn anode is proved to effectively inhibit Zn dendrites and control side reaction, hence exhibiting an ultrastable cycling (33 times longer than bare Zn foil) without obvious polarization. Benefiting from the optimal Zn anode and highly reversible Mn²⁺/Zn²⁺ hybrid storage mechanism, the Mn²⁺/Zn²⁺ HB shows an excellent cycling performance over 11 000 cycles with a 100% capacity retention. To the best of the authors' knowledge, it is the highest reported cycling performance and wide voltage window for AZBs with mild electrolyte, which may inspire a great insight into designing high‐performance aqueous batteries.     

Extended “Adsorption–Insertion” Model: A New Insight into the Sodium Storage Mechanism of Hard Carbons

Hard carbons (HCs) are promising anodes of sodium‐ion batteries (SIBs) due to their high capacity, abundance, and low cost. However, the sodium storage mechanism of HCs remains unclear with no consensus in the literature. Here, based on the correlation between the microstructure and Na storage behavior of HCs synthesized over a wide pyrolysis temperature range of 600–2500 °C, an extended “adsorption–insertion” sodium storage mechanism is proposed. The microstructure of HCs can be divided into three types with different sodium storage mechanisms. The highly disordered carbon, with d₀₀₂ (above 0.40 nm) large enough for sodium ions to freely transfer in, has a “pseudo‐adsorption” sodium storage mechanism, contributing to sloping capacity above 0.1 V, together with other conventional “defects” (pores, edges, heteroatoms, etc.). The pseudo‐graphitic carbon (d‐spacing in 0.36–0.40 nm) contributes to the low‐potential (<0.1 V) plateau capacity through “interlayer insertion” mechanism, with a theoretical capacity of 279 mAh g^?1 for NaC₈ formation. The graphite‐like carbon with d₀₀₂ below 0.36 nm is inaccessible for sodium ion insertion. The extended “adsorption–insertion” model can accurately explain the dependence of the sodium storage behavior of HCs with different microstructures on the pyrolysis temperature and provides new insight into the design of HC anodes for SIBs.     

Ultraviolet enhanced reactivation of a human virus: effect of delayed infection

The ability of UV-irradiated herpes simplex virus to form plaques was examined in monolayers of CV-1 monkey kidney cells preexposed to UV radiation at different intervals before virus assay. From analysis of UV reactivation (Weigle reactivation) curves it was found that as the interval between cell UV irradiation (0-20 J/m2) and initiation of the virus assay was increased over a period of five days, (1) the capacity of the cells to support unirradiated virus plaque formation, which was decreased immediately following UV exposure to the monolayers, increased and returned to approximately normal levels within five days, and (2) at five days an exponential increase was observed in the relative plaque formation of irradiated virus as a function of UV fluence to the monolayers. For high UV fluence (20 J/m2) to the cells, the relative plaque formation by the UV-irradiated virus at five days was about 10-fold higher than that obtained from assay on unirradiated cells. This enhancement in plaque formation is interpreted as a delayed expression of Weigle reactivation. The amount of enhancement resulting from this delayed reactivation was several fold greater than that produced by the Weigle reactivation which occurred when irradiated herpes virus was assayed immediately following cell irradiation.     

Changes In the Dna Labelling Index After β Irradiation of the Mouse Epidermis

This study looked at the changes in the interfollicular DNA labelling index (LI) with time after strontium-90/yttrium-90 β irradiation of approximately 100 mm² of mouse flank skin, after a dose of 100 Gy which produces transitory moist desquamation. Within 24 hr of such a dose the LI of the irradiated area was essentionally zero (0.07 ± 0.03%), whilst those of the side area and of the control area were 15.0 ± 2.6% and 21.4 ± 2.7%, respectively. the LI of the side and the control areas then fell within 3–5 days to approximately 4% and approximately 2% respectively, whilst that of the irradiated area rose rapidly to a peak value of 30.2 ± 1.7% at 10 days post-irradiation. There was a 20% reduction in the diameter of the area with detectable radiation damage within 5 days, and this is primarily due to cell proliferation and migration from the unirradiated margins of the field. In contrast, between days 10 and 20 the major source of repopulation is probably derived from local migration and proliferation of surviving hair follicle basal cells within the irradiated field.     

A Dual‐Carbon Battery Based on Potassium‐Ion Electrolyte

Although potassium‐ion batteries (KIBs) have been considered to be promising alternatives to conventional lithium‐ion batteries due to large abundance and low cost of potassium resources, their development still stays at the infancy stage due to the lack of appropriate cathode and anode materials with reversible potassium insertion/extraction as well as good rate and cycling performance. Herein, a novel dual‐carbon battery based on a potassium‐ion electrolyte (named as K‐DCB), utilizing expanded graphite as cathode material and mesocarbon microbead as anode material is developed. The working mechanism of the K‐DCB is investigated, which is further demonstrated to deliver a high reversible capacity of 61 mA h g^‐1 at a current density of 1C over a voltage window of 3.0–5.2 V, as well as good cycling performance with negligible capacity decay after 100 cycles. Moreover, the high working voltage with medium discharge voltage of 4.5 V also enables the K‐DCB to meet the requirement of some high‐voltage devices. With the merits of environmental friendliness, low cost and high energy density, the K‐DCB shows attractive potential for future energy storage application.     

The relationship between 59Fe uptake in marrow and 239Pu deposition in bone.

The marrow in the left femur of each of 17 mice was destroyed by X-irradiation and 59Fe and 239Pu uptake into both femurs was measured 1, 3 and 7 days later. Uptake of 59Fe into marrow was depressed in the left femur 1 and 3 days after irradiation but was enhanced in the right unirradiated femur 3 days after the left femur was irradiated. There was no corresponding depression of 239Pu uptake into the left irradiated femur or enhancement into the right unirradiated femur. These results do not support the view that a functioning erythropoietic marrow is necessary for 239Pu to be deposited in bone.     

Reversible Multivalent (Monovalent,Divalent, Trivalent) Ion Insertion in Open Framework Materials

The reversible electrochemical insertion of multivalent ions into materials has promising applications in many fields, including batteries, seawater desalination, element purification, and wastewater treatment. However, finding materials that allow for the insertion of multivalent ions with fast kinetics and stable cycling has proven difficult because of strong electrostatic interactions between the highly charged insertion ions and atoms in the host framework. Here, an open framework nanomaterial, copper hexacyanoferrate, in the Prussian Blue family is presented that allows for the reversible insertion of a wide variety of monovalent, divalent, and trivalent ions (such as Rb⁺, Pb²⁺, Al³⁺, and Y³⁺) in aqueous solution beyond that achieved in previous studies. Electrochemical measurements demonstrate the unprecedented kinetics of multivalent ion insertion associated with this material. Synchrotron X‐ray diffraction experiments point toward a novel vacancy‐mediated ion insertion mechanism that reduces electrostatic repulsion and helps to facilitate the observed rapid ion insertion. The results suggest a new approach to multi­valent ion insertion that may help to advance the understanding of this complex phenomenon.     

Sulfur/Oxygen Codoped Porous Hard Carbon Microspheres for High‐Performance Potassium‐Ion Batteries

Potassium‐ion batteries (KIBs) are very promising alternatives to lithium‐ion batteries (LIBs) for large‐scale energy storage. However, traditional carbon anode materials usually show poor performance in KIBs due to the large size of K ions. Herein, a carbonization‐etching strategy is reported for making a class of sulfur (S) and oxygen (O) codoped porous hard carbon microspheres (PCMs) material as a novel anode for KIBs through pyrolysis of the polymer microspheres (PMs) composed of a liquid crystal/epoxy monomer/thiol hardener system. The as‐made PCMs possess a porous architecture with a large Brunauer–Emmett–Teller surface area (983.2 m² g^?1), an enlarged interlayer distance (0.393 nm), structural defects induced by the S/O codoping and also amorphous carbon nature. These new features are important for boosting potassium ion storage, allowing the PCMs to deliver a high potassiation capacity of 226.6 mA h g^?1 at 50 mA g^?1 over 100 cycles and be displaying high stability by showing a potassiation capacity of 108.4 mA h g^?1 over 2000 cycles at 1000 mA g^?1. The density functional theory calculations demonstrate that S/O codoping not only favors the adsorption of K to the PCMs electrode but also reduces its structural deformation during the potassiation/depotassiation. The present work highlights the important role of hierarchical porosity and S/O codoping in potassium storage.     

Advanced Phosphorus‐Based Materials for Lithium/Sodium‐Ion Batteries: Recent Developments and Future Perspectives

High‐performance and lost‐cost lithium‐ion and sodium‐ion batteries are highly desirable for a wide range of applications including portable electronic devices, transportation (e.g., electric vehicles, hybrid vehicles, etc.), and renewable energy storage systems. Great research efforts have been devoted to developing alternative anode materials with superior electrochemical properties since the anode materials used are closely related to the capacity and safety characteristics of the batteries. With the theoretical capacity of 2596 mA h g^?1, phosphorus is considered to be the highest capacity anode material for sodium‐ion batteries and one of the most attractive anode materials for lithium‐ion batteries. This work provides a comprehensive study on the most recent advancements in the rational design of phosphorus‐based anode materials for both lithium‐ion and sodium‐ion batteries. The currently available approaches to phosphorus‐based composites along with their merits and challenges are summarized and discussed. Furthermore, some present underpinning issues and future prospects for the further development of advanced phosphorus‐based materials for energy storage/conversion systems are discussed.     

Structural Engineering of Hierarchical Micro‐nanostructured Ge–C Framework by Controlling the Nucleation for Ultralong‐Life Li Storage

The rational design of a proper electrode structure with high energy and power densities, long cycling lifespan, and low cost still remains a significant challenge for developing advanced energy storage systems. Germanium is a highly promising anode material for high‐performance lithium ion batteries due to its large specific capacity and remarkable rate capability. Nevertheless, poor cycling stability and high price significantly limit its practical application. Herein, a facile and scalable structural engineering strategy is proposed by controlling the nucleation to fabricate a unique hierarchical micro‐nanostructured Ge–C framework, featuring high tap density, reduced Ge content, superb structural stability, and a 3D conductive network. The constructed architecture has demonstrated outstanding reversible capacity of 1541.1 mA h g^?1 after 3000 cycles at 1000 mA g^?1 (with 99.6% capacity retention), markedly exceeding all the reported Ge–C electrodes regarding long cycling stability. Notably, the assembled full cell exhibits superior performance as well. The work paves the way to constructing novel metal–carbon materials with high performance and low cost for energy‐related applications.     

The influence of gamma radiation and substrate on mycotoxin production by Fusarium culmorum IMI 309344

Mycotoxin production (deoxynivalenol (DON), acetyl deoxynivalenol (A DON) and zearalenone) by Fusarium culmorum inoculated on to maize (heat sterilized, irradiation sterilized and non-sterile) and irradiated to 1 kGy or 3 kGy, or unirradiated, was investigated over a period of time. Lowest mycotoxin production was observed on non-sterile maize which may be due to the presence of a competitive microflora on non-sterile maize. In general, mycotoxin production was higher on heat-sterilized grain as compared to irradiation-sterilized maize. It was suggested that this pattern of mycotoxin production was possibly caused by changes in the grain brought about by autoclaving, which favoured mycotoxin production and possibly induced changes in irradiation-sterilized maize which inhibited mycotoxin production. On sterile maize, there was no significant difference in DON production by unirradiated, 1 kGy and 3 kGy irradiated cultures up to 56 d of incubation; between days 56 and 77 of incubation, DON production increased rapidly with largest increases occurring in irradiated (1 kGy and 3 kGy) cultures. On non-sterile grain, neither DON nor A DON were detected in unirradiated cultures of F. culmorum but were detected in cultures irradiated to 1 kGy and 3 kGy. In practice grain should be stored under conditions of temperature and moisture content which prevent fungal growth. However, in this study, the grain was stored under conditions that were approaching ideal for growth of the test organism. The results highlight that irradiation disinfestation of grain must be combined with good grain handling practices so that excessive mycotoxin production can be prevented during storage.     

Radiation-induced alterations in binding of concanavalin A to cells and in their susceptibility to agglutination

Cell susceptibility to agglutination mediated by a plant lectin, concanavalin A (Con A), and the binding capacity of Con A to cells following gamma-irradiation have been examined in mouse myeloid leukaemia cells cultured in suspension. Irradiation caused an immediate decrease in the amount of Con A bound to the cell surface, whereas susceptibility of irradiated cells to agglutination by Con A was unchanged when compared to that of the unirradiated cells. Post-irradiation incubation of cells at 37 degrees C resulted in a temporary, more than 1.3-fold increase in cell susceptibility to agglutination 60 min after irradiation, whereas binding capacity of cells for Con A gradually recovered following irradiation, reaching a comparable level to that of unirradiated cells 3 h after irradiation. Cell susceptibility to agglutination by Con A does not depend strongly on its binding capacity.     

Pseudo‐Zn–Air and Zn‐Ion Intercalation Dual Mechanisms to Realize High‐Areal Capacitance and Long‐Life Energy Storage in Aqueous Zn Battery

Aqueous zinc batteries are considered as promising alternatives to lithium ion batteries owing to their low cost and high safety. However, the developments of state‐of‐the‐art zinc‐ion batteries (ZIB) and zinc–air batteries (ZAB) are limited by the unsatisfied capacities and poor cycling stabilities, respectively. It is of significance in utilizing the long‐cycle life of ZIB and high capacity of ZAB to exploit advanced energy storage systems. Herein, a bulk composite of graphene oxide and vanadium oxide (V₅O₁₂·6H₂O) as cathode material for aqueous Zn batteries in a mild electrolyte is employed. The battery performance is demonstrated to arise from a combination of the reversible cations insertion/extraction in vanadium oxide and especially the electrochemical redox reactions on the surface functional groups of graphene oxide (named as pseudo‐Zn–air mechanism). Along with adjusting the hydroxyl content on the surface of graphene oxide, the specific capacity is significantly increased from 342 mAh g^?1 to a maximum of 496 mAh g^?1 at 100 mA g^?1. The surface‐controlled kinetics occurring in the bulk composite ensure a high areal capacity of 10.6 mAh cm^?2 at a mass loading of 26.5 mg cm^?2, and a capacity retention of 84.7% over 10 000 cycles at a high current density of 10 A g^?1.     

Effects of Gamma-irradiation on Lipid Metabolic Changes of Potato Tubers in Response to Mechanical Injury

Linolenic acid contents of glycolipids increased in irradiated potatoes during storage, accompanied by a decrease of linoleic acid. The puncturing of a potato tuber with a needle of a microsyringe caused the similar changes; the elevation of linolenic acid level and decline of linoleic acid were observed within 24 h after puncturing. Irradiation before the puncturing reduced the degree of the increase of linolenic acid in response to the mechanical injury. The rate of [¹³C]acetate incorporation into lipid fractions of irradiated tubers was smaller than that of unirradiated tubers, and polyunsaturated fatty acids (linoleic and linolenic acids) of lipid fractions were weakly labeled in irradiated tubers as compared with unirradiated ones. The results in this study indicate that irradiation retards lipid metabolism in response to mechanical injury.